Gangrene When Body Tissues Are Dead Or Dying Biology Essay

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We have noticed an abnormality in our cadavers right lower extremity. More specifically the right foot. The foot was discoloured, almost completely black and that led to the conclusion that he might have gangrene.

Gangrene (1,2,4,7,13) is a term that describes dead or dying body tissue(s) that occur because the local blood supply to the tissue is either lost or is not enough to keep the tissue alive. Gangrene has been recognized as a localized area of tissue death since earliest times. The Greeks used the term gangraina (1,2,5,7) to describe putrefaction (death) of tissue. In the health profession the term refers to tissue death due to loss of blood supply, although many people still associate the term with a bacterial infection. Therefore, a person can be diagnosed with gangrene but does not have to be "infected." (1,2,5,10,12,13)

There are two main types of gangrene referred to as dry and wet (1,2,4,5,6,8,11,). Many cases of dry gangrene are not infected. All cases of wet gangrene are considered to be infected, almost always by bacteria. The most common sites for both wet and dry gangrene to occur are the fingers and toes (like our cadaver) and other extremities (hands, arms, feet, and legs).

Wet (also sometimes termed "moist") (1,2,5,7,11) gangrene is the most dangerous type of gangrene because if it is left untreated, the patient usually develops sepsis and dies within a few hours or days. The primary cause of wet gangrene is due to oedema which applies pressure on the local blood supply. The restriction of local blood supply can also be caused by gas production, bacterial infection, etc. And ultimately leads to infection of the whole body. There are various conditions that can also compromise the blood flow and lead to infection of the specific area. For example cuts, burns (1,2,13) or vascular trauma.Wet gangrene is the type that is most commonly thought of when the term gangrene is used. Wet gangrene often produces an oozing fluid or pus, hence the term "wet."

Dry gangrene (1,2,5,9,12), if it does not become infected and progress to wet gangrene, usually does not cause sepsis or cause the patient to die. However, it can result in local tissue death with the tissue eventually being sloughed off. Usually, the progression of dry gangrene is slower (days to months) than wet gangrene because the vascular compromise slowly develops due to the progression of diseases that can result in local arterial blockage over time. There are many diseases that may lead to dry gangrene; the most common are diabetes (1,2), arteriosclerosis (7), and tobacco addiction (smoking) (5,6,9). Infrequently, dry gangrene can occur quickly, over a few hours to days, when a rapid arterial blockage occurs (for example, arterial blood clot in the blood suddenly occludes a small artery to a toe). Dry gangrene often produces cool, dry, and discoloured appendages (sometimes termed "mummified") with no oozing fluid or pus, hence the term "dry." (1,2,5,9,12)

The ordinary reason of either wet or dry gangrene (1,2,4,5,7,8,13)is loss of an effective local blood supply to any tissue. Loss of the blood supply means tissues are deprived of oxygen, thus causing the cells in the tissue to die. The most common causes of tissue blood supply loss are infections, trauma, and diseases that can affect blood vessels (usually arteries).

The symptoms of gangrene vary according to the type of gangrene (wet or dry), the anatomic location (external versus internal sites), and which organ system(s) are affected.

Dry gangrene often begins with the affected area first becoming numb and cool. Discomfort levels vary with the patient's perception. The local area (for example, toe or finger) (5,13) then starts to discolour, usually turning from reddish to brown and eventually black. During this time, the local area shrinks, becomes dry (mummified), and may slough off the body. Dry gangrene caused by immediate loss of arterial blood supply can first turn pale or bluish and then progress as above.

Wet gangrene, in contrast to dry gangrene, usually begins with swelling and a very painful affected area that may be initially red and show signs of decay (sloughing tissue, pus, local oozing of fluid). Often the fluid and the affected area develop a very bad smell, due to the presence of such foul-smelling compounds as cadaverine and putrescine, (1,2,5,6,7,10,13) which are produced as the infectious agent(s) destroy tissue. This dead and dying tissue develops a moist and black appearance. One of the additional symptoms that might be seen is fever (9) and other signs of sepsis.

Internal gangrene, a variant of wet gangrene, has less obvious initial symptoms because the wet gangrene occurs in the internal organs. The patient may be very ill (septic) with gangrene but show few if any visual symptoms that are characteristic for wet gangrene. Occasionally, the skin overlying an organ with wet gangrene may become reddish or discoloured, and the area may become swollen and painful. When the surgeon exposes the infected organ, the signs of wet gangrene are apparent. The symptoms may vary due to the different organs affected. For example, patients with gangrene of the bowel due to an incarcerated hernia (7) can have severe pain at the site of the hernia while a gangrenous gallbladder can result in severe pain located in the upper right side of the abdomen.

If the tissue has enough oxygen to not get infected, wet and dry gangrene can be prohibited. Other factors like smoking and frostbite leaves you more prone for gangrene, thus by avoiding them you are decreasing your risk. In developed countries gangrene can be prevented by stabilizing the glucose levels in diabetic patients and examine their feet daily to check for any signs of redness, infection or cuts. A patient with loss of sensation of any part of the foot should do this daily to see if the situation is worsening and if so go to your doctor immediately. (1,2,5,8)

If any wound or burn occurs, it should be treated immediately to prevent infection. This is especially important in people with diabetes, vasculitis, (7) or a compromised immune system.

Some patients that notice coolness and redness of a local area (for example, toes, fingers) and get an angiogram that shows arterial blockage can have successful prevention of dry gangrene (and possibly wet gangrene) if the vascular surgeon can remove the clot or hindrance in the artery before local tissue dies.

This disease is thus treatable is detected early.